Fabric and method of making the same



m ted July 24, 1.934

UNITED STATES PATENT OFF ICE I M 4 1,987,267 n FABRIC METsH ggE OF MAKING THE William Bennett Serrlngton,

Boston, Mass, as-

signor, by direct and mesne assignments, to Charak Chemical Company, Boston, Mass., a corporation of Massachusetts 1 No Drawing. Application August 7, 1929,

Serial No. 384,236

8 Claims.

The present invention relates to methods of treating fabrics and to the fabrics produced thereby. The object of the invention is to produce a new and improved fabric that, though not strictly waterproof, is water shedding or solved in a suitable solvent.

repellent, and which, therefore, may be cleaned by the' mere application of water, without thorough washing, and that is as flexible and pliable as the original fabric before treatment.

- The fabric is first immersed in a liquid comprising a suitable water-shedding substance dis- A very satisfactory water-shedding substance is a nitro-cellulose solution or a cellulose compound; like pyroxylin ordinary nitro-cellulose or cellulose acetate. Ethyl acetate or other acetate may be used for the solvent, but it is preferred to employ the product marketed by the Du Pont Company as No. 3065. In order not to affect the flexibility and softness of the ultimate fabric, a softening agent is employed, such as parafiln waxes, oils, and. other substances, as hereinafter explained. Avery efficient mixture, for certain types of fabrics, is 12 parts solvent to 1 part wax and 1 part nitro-cellulose. The wax, heated and in liquid form, is first added to the solvent and stirred, after which the cellulose derivative paste this solution, the fabric is led to any device for thoroughly impregnating it with the liquid, such as one or more pairs of squeezing rolls. Scrapers or similar mechanisms may also be employed, but the results are not then quite so effective. The solution penetrates the cloth, but not so deeply. The use of squeezing rolls or their equivalent is, therefore, preferred, be-

cause causing the solution to be driven or forced into the fabric, Inaddition to this function, the rolls also act to remove the excess liquid from the fabric. An excess of the liquid might introduce an undesirable stiffness in the fabric. The cloth is then allowed to dry. This may be done in the open air, but the drying process may be hastened by a drying fan, or the application of heat, such as by the use of drying boxes,

pressing with hot irons, or using mangling rolls.

improper proportions are used, for example,

the paraffin may separate out from the cellulose, producing an undesirable, white-deposit effect. If the threads of the cloth form a large mesh, some of the water may even pass through the cloth, but without in the slightest wetting the fabric. The water simply does not penetrate the cloth. It follows from this property that any dirt or stain, unless it be of a nature that at tacks the celluloid-which is not often the case,may be washed from the cloth merely by applying water, as with a moist cloth, to dissolve away the dirt or stain. The cloth may, indeed, be actually washed orlaundered in the ordinary way, using boiling water; and after drying, it may even be pressed with hot irons. The fabric will still retain its originally endowed property of shedding or repelling water, and it will not have been injured in the slightest by this treatment. The fabric may also be cleansed with gasoline or other cleansing fluids without affecting its water-repelling quality.

Though the above-mentioned proportions are found to be preferable, and applicable to almost any fabric, they may be varied as desired, and particularly according to the nature of the fabricemployed. Using the same unit proportions of wax and cellulose derivative, for example, the proportion of solvent may be increased to as much as 100, if desired. The proportions of wax' and cellulose derivative may also be varied. Thus, it is possible to use one part solvent, oneeighth part wax and one-half to, one part cellu-. lose derivative. The above proportions of 12 to 1 to 1 are found to be very eflfective for sateens, silks, silk crepes, cotton goods, woollen goods and cretonne. If, however, a heavier body, like duck, canvas, etc., is treated, it may be desired to vary the proportions so as to have, for example, five parts of solvent to one part wax and one part cellulose derivative, thus to give a heavier body to the liquid. Using such heavier mixtures, and applied to such heavier fabrics,

the water-shedding properties begin to take on Waterproofed products are usually much harder and stiffer than is characteristic of the present invention. Other softening agents for increasing the flexibility of the goods may be employed instead of wax, such as animal and vegetable fats, greases, or oils, like cottonseed oil, machine oil, linseed oil, castor oil, glycerine, gums, like shellac and gum arabic, gelatine, fish glue, etc. Some of these substances, such as glue and gums, are themselves, to a greater or lesser degree, water-shedding. At, times, these substances may be used in 'combination,--for example, both wax and oil may be used in the same solution. An emulsion of soap and water may, if desired, be added to the softening agent. The water evaporates away, leaving the emulsion of the oil or wax and soap which can then be dissolved in a suitable solvent. Other substances may, of course, also be added, depending upon the nature of the results desired. In all cases, it should, however, be borne in mind that the additional substances should not materially interfere with the penetration of the cellulose derivative and wax, or their equivalents, into the fabric. Thus, benzine, or naptha; or turpentine, though all good solvents of paraffin wax, can not dissolve the cellulose derivative. If, therefore, for some reason, some such non-solvent of the cellulose derivative is desired to be used for some specific purpose, it must be used in small enough quantities so as not to interfere with the penetration of the cellulose derivative into the fabric. Usually, no such non-solvent is desirable, for benzine, for example, seems to have a tendency to introduce a usually unwanted unevenness of fibre and harshness in the fabric. like benzine, furthermore, by preventing penetration of the cellulose derivative into the cloth,

have a tendency to cause the cellulose deriva-- tive to peel away from the fabric. Fabrics treated with benzine or its equivalent, moreover will peel, because the. benzine prevents the penetration of the cellulose derivative; while the present invention results in an intimate union between the cellulose and the fabric, the cellulose derivative of which can not peel. The proportions of emulsion to solvent maybe as little or as great as desired, say from /2 of 1% to 150%. g

Further considerations leading to the proper proportions will depend upon the color of the goods, as some proportions will cause the colors to run, and others will not. Where white goods are employed, alum or camphor dissolved into the solvent with the oil or the wax will increase the whiteness. A very slight amount of alum or camphor .is required for this purpose. Coloring matters, or bronze or other powders, may be added to the solution if it is desired to color or bronze the fabric while treating it. When bronze powders are used, it is preferred to coat one side only of the fabric with the solution, as bronzing is not ordinarily desirable on both sides of the fabric. Even in such cases, the cellulose derivative will be found to penetrate into the cloth. Indeed, unlessthe fabric is very thick, it may go through the cloth to the other side. The bronzing however, shows under the microscope as discreet particles.

The theory of the operation is not fully'understood. The volatile constituents of the solvent evaporate away, seeming to cause the cellulose derivative, thus dried out, to contract in against the various parts of the fibers of the fabric.

Solvents 7 The waxor oil or its equivalent seems to coalesce with the cellulose derivative when in the fabric to form a unitary substance having considerably greater flexibility' than the cellulose derivative alone, but without substantially affecting the body of the resulting product. Whatever may be the theory, it is found that, though the flexibility of the fabric is unimpaired, the cellulose derivative has-penetrated deeply into the cloth, apparently becoming a permanent part thereof. It is to this penetrating effect, indeed, that the non-peeling character of the softened cellulose derivative is probable due. As the individual threads 'are thus impregnated with the softened cellulose derivative, they will float in water without absorbing any of it. The untreated threads, as is well known, will soak up water like a sponge. The untreated thread, under the microscope, shows a fuzzy, bunchy, uneven surface over each strand of the thread, while the treated thread has the appearance of a well defined, compact, smooth, unbroken surface. The flexibility of the fabric isv in part believed to be due to the fact that so comparatively little of the solution is left in the goods after the squeezing rolls have acted to drive out the excess liquid. If large quantities of the liquid were permitted to dry on the fabric, it might leave the cellulose derivative in more or less of a harsh, coarse, stiff-sheet form, instead of merely acting upon the individual fibers of the cloth, to produce the fine, soft, pliable, flexible article of the present invention.

In the claims, the term textile fabric will be employed to denote fabrics of the above-mentioned character, porous and constituted of fibrous materials.

What is claimed is:

1. The process of treating textile fabrics which consists in immersing the fabric in a volatile solvent in which are dissolved a plastic and a softener both of which are water-repellent, the plastic being resistant to the attacks'of heated washing fluids, and the plastic and the softener when united together in, and with, the fabric being as a unit resistant to the attacks of the heated washing fluids, removing the excess solution from the threads of thefabric and from between said threads so as to leave only sufficient to impregnate the individual threads to render the fabric water-repellent but of substantially the same flexibility and pliability as the original fabric, and evaporating the remainder of the solvent to cause the plastic and the softener to become united together and to become united with and impregnated within, but not substantially between, said threads.

2. The process of treating textile fabrics which consists in immersing the fabric in a volatile solvent in which are dissolved an amorphous organic plastic and an organic softener both of which are water-repellent, the plastic being resistant to the attacks of heated washing fluids, and the plastic and the softener when united together in,

and with, the fabric being as a unit resistant to mainder of the solvent to cause the plastic and the softener to become united together and to become united with and impregnated within, but not substantially between, said threads.

3. The process of treating textile fabrics which consists in immersing the fabric in a volatile solvent in which are dissolved an amorphous organic plastic and a wax both of which are waterrepellent, the plastic being resistant to theattacks of heated washing fluids, and the plastic and the wax when united together in, and .with, the fabric being as a unit resistant to the attacks of the heated washing fluids, removing the excess solution from the threads of the fabric and from between said threads so as .to leave only suflicient to impregnate the individualv threads to render thefabric water-repellent but of substantially the same flexibility and pliability as the original fabric, and evaporating'the remainder of the solvent to cause the plastic and the wax to become united together and to become united with and impregnated within, but not substantially between, said threads.

4. The process of treating textile fabrics which consists in immersing the fabric in a volatile solvent in which are dissolved a cellulose derivative and a wax both of which are water-repellent, the cellulose derivative being resistant to the attacks of heated washing fluids, and the cellulose derivative and, the wax when united together in, and with, the fabric being as a unit resistant to the attacks of the heated washing fluids, removing the excess solution from the threads of the fabric and from between said threads so as to leave only sufficient to impreghate the individual threads to render the fabric water-repellent but of substantially the same flexibility and pliability as the original fabric, and evaporating the remainder of the solvent tocause the cellulose derivative and the wax to become united together and to become united with and impregnated within, but not substantially between, said threads. 1

5. The process of treating textile fabrics which consists in immersing the fabric in a volatile solvent in which are dissolved a cellulose derivative and an oil both of which are water-repellent, the cellulose derivative being resistant to the attacks of heated washing fluids, and the cellulose derivative and. the oil when united together in, and with, the fabric, being as a unit resistant to the attacks of the heated washing fluids, removing the excess solution from the threads of the fabric andfrom between said threads so as to leave only suiiicient to impregnate the individual threads to render the fabric water-repellent but of substantially the same flexibility and pliability as the original fabric, and evaporatng the remainder of the solvent to cause'the cellulose derivative and the oil to become united together and to become united with and impregnated within, but not susbtantially between, said threads. 7

6. The process of treating textile fabrics which consists in immersing the fabric in a volatilesolvent in which .are dissolved a cellulose derivative, a wax and an oil all of which are waterrepellent, the cellulose derivative being resistant to the attacks of heated washing fluids, and the cellulose derivative, the wax and the oil when united together in, and with, the fabric being as a unit resistant to the attacks of the heated washing fluids, removing the excess solution from the threads of the fabric and from between said threads so as to leave only suflicient to impregnate the individual threads to render the fabric water-repellent but of susbtantially the same flexibility and pliability as the original fabric, and evaporating the remainder of'the solvent to cause the cellulose derivative, the wax and the, oil to become united together and to become united with and impregnated within, but not substantially between, said threads.

7. The process of treating textile fabrics which consists in immersing the fabric in a volatile solvent in which are dissolved cellulose nitrate, a wax and an oil all of which are water-repellent, the cellulose nitrate being resistant to the attacks of heated washing fluids, and the cellulose nitrate, the wax and the oil when united together in, and with, the fabric being as a unit resistant to the attacks of the heated washing fluids, removing the excess solution from the threads of the fabric and from between said threads so as to leave only sufllcient to impregnate the individual threads to render the fabric water-repellent but of substantially the same flexibility and pliability as'the original fabric,

and evaporating the remainder of the solvent to to become united together and to become united with and impregnated within, but not substantially between, said threads.

8. The product of the process of claim 1, being a textile fabric having a plastic and a softener united together and united with and impregnated within, but not substantially between, the individual threads thereof in quantity only sufficient to render the fabric water-repellentbut of substantially the same flexibility and pliability as the original fabric, the plastic and the softener both being water-repellent, the plastic being resistant to the attacks of heated washing fluids, and the plastic and the softener when united together in, and with, the fabric being as a unit resistant to the attacks of the 

